I don’t want to tell my work 😭

I keep putting it off. I’m currently almost 17 weeks and I work at a large law firm. I don’t want people to look at me different, talk behind my back, or possibly replace me. I have been here for years so I’m not worried about getting fired but maternity leave here is only 6 weeks and I cannot imagine only taking 6 weeks off when I’ve just given birth. How did you tell your boss/coworkers? How did it go?